Some considerations on the use of Lα series of transition metals in electron probe microanalysis: The example of zinc minerals

Abstract

AbstractIt is shown, using measurements on certain zinc minerals, that the Lα emission of transition metals can be affected as follows. First, the band shape is often changed in the range of the satellite emission which implies, for data acquisition, the use of the total band area instead of the measurements at the peak maximum. Second, the physical process of self‐absorption of Lα photons (here, the absorption of Zn Lα in Zn) depends on the nature of the specimen (metal, semiconductor, insulator), In EPMA, the corresponding theoretical parameter, which is the mass self‐absorption coefficient, may be then changed between an unknown and standard, despite the assumption of constancy in matrix‐effect correction models. Both phenomena are correlated because of their strong dependence on the electronic structure of the M5 level, which can be modified in poor conducting materials by the presence of holes. The choice of suitable standards is then crucial in order to perform accurate k‐ratio measurements.